Television gaming apparatus

ABSTRACT

Apparatus and methods are herein disclosed for use in conjunction with standard monochrome and color television receivers, for the generation, display and manipulation of symbols or geometric figures upon the screen of the television receivers for the purpose of playing games. The invention comprises in one embodiment a control unit, connecting means and in some applications a television screen overlay mask utilized in conjunction with a standard television receiver. The control unit includes the control means, switches and electronic circuitry for the generation, manipulation and control of video signals which are to be displayed on the television screen. The symbols are generated by developing current pulses proportional to predetermined portions (slices) of horizontal and vertical sawtooth waves. The connecting means couples the video signals to the receiver antenna terminals thereby using existing electronic circuits within the receiver to process and display the signals. An overlay mask which may be removably attached to the television screen may determine the nature of the game to be played. Control units may be provided for each of the participants. Alternatively, games may be carried out in conjunction with background and other pictorial information originated in the television receiver by commercial TV, closed-circuit TV or a CATV station.

[ William T. Rusch, Hollis, NH,

1 inventor:

} Assignce:

i 340-109 SR g y XFZ RE ZBsSQ? i i i W United 5 E Re. 28,507 RuschReissued Aug. 5, 1975 TELEV LSION GANHNG APPARATUS PrimaryExaminer-David L. Tralton Attorney. .igcnt or FirmLouis Etlingcr;Richard I. Seligman Nashua. NH.

:21 Filed: Apr. 25, 1974 [571 ABSTRICT 1 A I NO 464 256 Apparatus andmethods are herein disclosed for use in Related US. Patent DocumentsReissue oi":

[64] Patent No.: 3,659,284

kgued Apr 1972 playing games. The invention comprises in one em- A I8281;; bodiment a control unit, connecting means and in r 5 1969 someapplications a television screen overlay mask utilized in conjunctionwith a standard television re- [m] U 9 C] 340/3", fif 773/8; ceiver. Thecontrol unit includes the control means. i Q i I switches and electroniccircuitry for the generation. H1] [m C! 2 G08B 5/36 manipulation andcontrol of video signals which are to 5 Fieid 315/377 be displayed onthe television screen. The symbols are i i 4 i i i a generated bydeveloping current pulses proportional [56} References Cited topredetermined portions [slices] of horizontal and vertical sawtoothwaves, The connecting means cou- 7 UNITED STATES PATENTS pies the videosignals to the receiver antenna terminals 11155993 -i- Goldsmllh at 31532 thereby using existing electronic circuits within the re 39 g g-D0211 325? ceiver to process and display the signals. An overlay 1: 2:mask which mil) be removably attached to the televi- 'a 71x96: Hgmhrm "Hsion screen may determine the nature of the game to 9/196; 6135 atulum'm be played. Control units may be provided for each of 1158358 HHQMRagmI at L VVVV 340/334 AD the participants. Alternatively, games may hecarried 3349796 5/1966 M m H 3 5 33 out in conjunction with backgroundand other picto- 3.497 760 2/1970 Kiesling H S/6.8 X rial informationoriginated in the television receiver by FORFIGN, PATENTS ORAPPLICATIONS commercial TV closed-circuit TV or a CATV station. some6/1959 France 64 Claim$- 35 Drawing Figures W 63.5 vs l srnc i E as E33Ll E a +Er\ fl l 'H FHZG m i ls mc/ L D \l F l i SAWTQQTH l 4TH i I, 38l i l eentnaron m SUCER 36 hc l 1 SPOT l st; MS i an.

'TT i l W l r L :Ms J34 V l c" 1 [JR g l SPOT l l l GATE sniffCOlNCiDENCE a SYF'C GATE 3. 23:25.. ---*a-* 630115 l 'T/\\' 4s rv 'r l Il l "T 3' HOR. smc/ l SAWTOOTH l GEN 31 l or COlNCIDENCE ATE VERT smc/SAWTOOTH F. GEN 32 I B, 1: V I v 0* b d conjunction with standardmonochrome and color television receivers. for the generation. displayand manipulation of symbols or geometric figures upon the screen of thetelevision receivers for the purpose of 16 Sheets-Sheet 1 FIG! mvsmw 3OWILLIAM T. RUSCH A BY A TTORNE) Reiasueri Aug. 5, 1975 I Re. 5%?

16 sheets-si n 4 W (BI m g (D) (E) (F) FIG. 6

I\[\ HOR 38 IHI SYNC/ M H SAWTOOTH w 6V SPOT! VIDEO GEN. 47/

0-. VIDEO TH; VOLTAGE GN L I\1\ 10D RF N osc.

VERT SYNC/ M SAWTOOTH GEN. 49

0- 6V :52 46 TV VOLTAGE I ISPOTI I I SPOT I ICOINCIDENCE| IGATING PULSEI VARIABLE SEVERALI I I I THRESHOLD? I SPOTS I I FIGS { FIG? 511sWILLIAM T. RUSCH L g 6M ATTORNEY Reissued Aug. 5, 1975 16 Sheets-Shet 1oFIGIZD SPOT 2 GEN V SPOT H GEN INTEGRATO R INVENTOR.

WlLLIAM T. RUSCH EFMD 1% Reiasued Aug. 5, 1975 16 Sheets-Effect 12 TOSPOT 3 GENERATOR POSTTION FUP- FLOP T'S'T'T TO SPOT GEN.

TO SPOT 3 GENERATOR HTT" SPOT WITH T55 WALL BOUNCE SYSTEM V TO SPOTZ T 8e T STRAIGHT STRAIGHT CONTROL CONTROL JOYSTICK JOYSTICK PLAYER A PLAYERB I IO [5 B INVENTOR.

WILLIAM T. RUSCH A T TORNF Y Reiasued Aug. 5, 1975 Re. 23,507

16 Sheets-Sheet 13 I58 ---4 N FEGRATOR T |e4 162 p HORIZONTALCIOMPAQATOR F GENERAL W60 FLIP-FLOP I63 0 SYSTEM VERTICAL I65 FLWFLOPCOMPARATOR O H 5 4 INTEGRATOR COINCIDENCE GENERAL SYSTEM DETECTOR ANDCROWBAR [i3 FJGITB JM'ENTOR. WILLIAM T. RUSCH ATTORNEY Reissued Aug. 5,1.9?5 Re. 28,507

16 sheets-51198155 CONVENTIONAL TELEVISlON 1551 RECEIVER VERTICAL E EENN "205 O IO GTRGOTTRY i SQ Q 195 I ZONTAL 202 VIDEO DEFLECTION 204 m fAMPUFIER CIRCUITRY 2034? use i BOEFEQ [BUFFER 20? 1 8V! 206 F V HT SPOT1 491 OR GATE ANO PULSE SHAPER GEN.

VERT|OAL HORTZONTAL SYNC. SYNC. SAWTOOTH SAWTOOTH GENERATOR GENERATOR N5J lgs 1 SPOT l v GEN. HI

1 OR GATE i- AND PULSE Y AMPLIFIERS |92 T SHAPER 209 SPOT n I93 208 GEN8Hn 225 VERT|cAL VERTICAL DEFLECTION AMPUFIERS 224 OscTLLATOR ,22?HORTZONTA? HORlZONTAL OsciLLATOR AMPLIFIERS HIGH 22s- VOLTAGE RECTIFIERMENTOR WILLIAM T. RUSCH A TTORNE Y Reissued Aug. 5, 1975 Re. 23,507

16 Sheets-Shaat 16 FIG. 20

Q N g;

Hg N I I g o g) A u Q: I 5 ig '8 m s ow psm O %55 55 x 11079 $60INVENTOR. F WILLIAM T. RUSCH wa Magg ATTORNEY TELEVISION GAMINGAPPARATUS Matter enclosed in heavy brackets I: 1 appears in the originalpatent but forms no part of this reissue specification; matter printedin italics Indicates the additions made by reimue.

This invention relates to the subject matter disclosed in applicationSer. No. 126,966 filed Mar. 22, 1971, a continuation of application Ser.No. 697,798 tiled Jan. 15, 1968, now abandoned; and application Ser. No.713,862, filed Mar. 18, 1968, now U.S. Pat. No. 3,497,829.

BACKGROUND OF THE INVENTION This invention relates to an apparatus andmethod by means of which standard television receivers can be utilizedas active rather than passive instruments. This is accomplished incertain embodiments by having participants manipulate controls of acontrol unit connected to the television receiver to cause a symbol,such as a rectangle, circle, ring, star, cross, spot or a plurality ofspots, to be displayed upon the television screen by means of which theparticipants can play a variety of games, participate in simulatedtraining programs, as well as carry out other activities. By way ofexample, modified versions of the well-known game of ping-pong may beplayed by two participants by physically or electronically placing anappropriate mask rep resenting the net upon the screen of the televisionreceiver. Three displayed spots represent two paddles and a ball whereinthe ball is moved in a particular di rection when hit by a paddle.

Heretofore, color and monochrome television receivers have been usedgenerally by the home and other viewers as passive devices; i.e., thetelevision receiver is used only as a display means for programmingoriginating at a studio. The viewer is limited to selecting thepresentations available for viewing and is not a partici pant to theextent that he can control or influence the nature of, or add to thepresentation displayed on the receiver screen.

A standard receiver employed with auxiliary equipment to provide anactive form of home entertainment is described in a patent applicationfor Television Gaming and Training Apparatus," Ser. No. 126,966 filedMar. 22, 1971 a continuation ofSer. No. 697,798, filed Jan. 15, 1968,and assigned to the assignee of this application. Since most homes areequipped with television receivers, the only cxpense required to provideadded family enjoyment is the expense ofa control unit of one type oranother.

SUMMARY OF THE INVENTION Accordingly, it is an object of the presentinvention to provide apparatus and methods for displaying video signalson the screen of a television receiver, where some or all of the videosignals are both generated and controlled by apparatus external to thetelevision receiver.

It is another object of the present inven .t i on to provide anapparatus and method wherein a standard color or monochrome televisionreceiver is utilized as an active instrument for playing various typesof games involving one or more participants.

It is a further object of the present invention to provide a devicewhereby an individual may pit his alertness, skill, manual dexterity andvisual acuity against automatically controlled video displays.

It is yet a further object of the present invention to provide anapparatus which will generate spots such as squares, rectangles,circles, rings, stars, etc. which may be controlled by one or moreparticipants for playing various types of games.

It is another object of the present invention to provide a cathode raytube apparatus for displaying symbols to be manipulated by participants.

It is yet another object of the present invention to provide anapparatus which will allow one or more participants to actively use astandard television set while receiving background and other pertinentpictorial information from a cooperative commercial TV, closedcircuitTV, or CATV station, thus combining or alternating studio andhome-generated information on the TV screen.

It is still another object of the present invention to allow the use ofstandard TV set for gaming or other activities without the need for anykind of internal electrical connection to the TV set for theintroduction of video and/or chroma signals, connections being requiredto be made only to the externally-accessible antenna terminals.

In accordance with one embodiment of the present invention, a televisiongaming apparatus is provided for generating video signals in accordancewith the standardized television format, which signals may be controlledby an individual operator by means of a joystick or other manuallyoperative meansv The television gaming apparatus comprises controlapparatus having included therein the necessary electronic circuits toproduce video signals which are compatible with standard televisionreceivers.

The control ipparatus has video signal control means mounted thereon foreach access and connecting means are provided for coupling the videosignals generated within the control box to the television receiver.

By way of illustration, the television gaming apparatus can be used forplaying a game of ping-pong by providing on a TV screen two spots whichrepresent paddles. Means are provided for enabling the players tocontrol the vertical movement of the spots. Mears are also provided forgenerating on the screen of the elevision receiver a third spot whichrepresents the ping pong ball, which spot automatically moves from anoffscreen left position on an off-screen right position and vice versaunless hit by a paddle spot whereupon the ball spot will changedirection. The players have further controls for changing the verticalposition of the ball spot.

Suitable overlays or presentations from a cooperative TV station may beused in conjunction with said games to enhance the asthetic appealthereof.

BRIEF DESCRIPTION OF THE DRAWINGS The above-mentioned and other fcatureand objects of this invention will become more apparent by reference tothe following description taken in conjunction with the accompanyingdrawings, in which:

FIG. I is a pictorial view illustrating the principle components of anembodiment of the invention;

FIG. IA is a pictorial view illustrating an alternate embodiment for thecontrol unit of FIG. I;

FIG 2 is a sketch illustrating a typical TV screen and overlay mask asemployed in an embodiment of this in \ention;

FIG. 3 is a sketch illustrating the manner in which spots are formed ona TV screen;

FIG. 4 is a block diagram illustrating the spot generation:

FIG. 5 is a block diagram of the preferred mode of generating spots on aTV screen;

FIG. 6 is a plurality of sketches illustrating shapes of representativespots;

FIG. 7 is a schematic of a sync/sawtooth generator employed in theembodiment of FIG. 5;

FIG. 8 are schematics ot'circuits employed in the emhodiment of FIG. 5;

FIG. 9A is a schematic of potentiometer controls used to generate slicercontrol voltages;

FIG. 9B is a schematic ofjoystick controlled potenti' ometcrs used togenerate slicer control voltages;

FIG. 9C is a schematic of joystick controlled potentiometer-integratorcontrol used to generate slicer control voltages;

FIG. IUA is a schematic of a position flip-flop circuit used to controlspots in certain applications of this invention;

FIG. 10B are sketches of representative waveforms of the circuit of FIG.10A:

FIG. I IA is a block diagram of apparatus of control ling a "hit" spot;

FIG. I I8 is a sketch illustrating the manner in which the apparatus ofFIG. IIA controls a hit spot; supplies] FIG. IIC is a schematic of thehorizontal gated differentiator of FIG. IlA;

FIG. I ID is a schematic of the bilateral switch, integrator and wallbounce control of FIG. IIA;

FIG. 12A is a diagram of apparatus for a simulated ping-pong game;

FIG. 12B is a sketch of a TV screen illustrating the manner of play ofthe pingpong game of FIG. 12A;

FIG. IZC is a sketch of a TV screen illustrating the manner of play of asimulated hockey game using the apparatus of FIG. 12A;

FIG. 12D is a sketch of a TV screen illustrating the manner of play of asimulated baseball game;

FIG. I3 is a sketch illustrating a class of games (chase" games) whichcan be played using the apparatus of this invention;

FIG. 14 is a diagram of apparatus for a siimulated hockey game;

FIG. ISA is a diagram of apparatus for the simulated handball game;

FIG. 15B is a sketch of a TV screen illustrating the manner of play of asimulated handball game using the apparatus of FIG. 15A;

FIG. 16A is a diagi am of apparatus for a simulated pinball game;

FIG. 16B is a sketch of a TV screen illustrating the manner of play of apinball game using the apparatus of FIG. I6A;

FIG. 17A is a diagram of apparatus for a simulated bowling game;

FIG. I78 is a sketch of a TV screen illustrating the manner of play of abowling game using the apparatus of FIG. 17A.

FIGS. IBA ISC are block diagrams ofbuilt-in" em bodiments of theinvention;

FIG. I) is a simplified block diagram of another embodiment of-TV gamingapparatus; and

FIG. 20 is an alternate embodiment of circuits em ployed in theembodiment of FIG. 5.

DESCRIPTION OF PREFERRED EMBODIMENTS The principal components of oneembodiment of a television gaming system configured according to theinvention are illustrated in FIG. I which is a pictorial view showing atelevision receiver 10 a control unit 14 and means I2 for connectingcontrol unit 14 to receiver Ill. The television receiver I0 employed canbe any of the standard commercially available models that are generallyused for home entertainment. Either a monochrome or color television setmay be used with the present invention since the basic principles of theinvention apply to both types. The connection means 12 is in thisembodiment a shielded cable, for example. shielded twin lead, and isattached to the antenna terminals of receiver 10 in conventionalfashion.

Control unit 14 generates video signals shown as spots 20,. 20 and 21.The spots 20, and 20 are positioned on the receiver screen 18 by knobs16,, I7 and 16 17 respectively. For clarity. the spot 21 is illustratedas a circle and the spots 20 are illustrated as diamonds. however, manyshapes can be generated. In the devices to be described hereinafter,circles are generally employed.

Knob 16 controls the vertical position of spot 20 while knob 17 controlsthe horizontal position thereof. Thus, it can be seen that the spot 20,may be positioned at any point on the screen by the proper manipulationof knobs I6 and I7. Spot 20-; is positioned in like manner by knob 16 I7In this embodiment spot 2] is automatically positioned on screen I8without manual control. This will be described more fully hereinafter. Areset switch 26 is shown on the control unit 14 and is used to reset thepicture on the television screen. For example, a game may be played inwhich one spot is to be positioned over the other and when this isaccomplished one spot will disappear and the background will changecolor. When games of this nature are played, a reset means is requiredbefore play can be resumed. Reset switch 26 performs this function.

A knob I5 controls background color for color TV receiver applicationswherein a chroma generator is employed in the manner set forth in saidapplication Ser. No. b16966. Alternatively, control unit 14 maybe brokenup into a master control unit containing the electronic circuits andindividual control units containing control knobs 16,, 17 and 16 17whereby each participant may operate from a position away from the otherand so not to interfere with other players. This is illustrated in FIG.IA wherein control unit 14 is broken up into a master control unit 27and individual control units 22 and 23. The master control unit 27contains the electronic circuitry found in control unit I4 and controls26 and IS. Knobs l6, l7 and 16,, I7 which position the spots 20 and 20are situated on individual control units 22 and 23 respectively.

The knobs I6, 17 may be combined into a singlejoy stick permittingcontrol of the horizontal and vertical spot positioning by a singlecontrol means.

Other spot position and control means (not shown) can be incorporatedinto the control unit(s) and these will be described hereinafter.

Rather than provide a separate control unit. the electronic circuitry ofthe control unit could be built into the television receiver as aconstituent part thereof and the receiver sold as both an active andpassive home cnterfainment system. Control units containing the actualmanipulating controls can be provided as above,

A typical sequence of steps to play a game using the present inventionwould he as follows: 1. Attach connection means 12 to TV set ll) at theantenna terminals thereof. if not already attached; 2. turn the TV seton: 3. select the proper channel on the set for the control unit beingused; 4. apply power to the control unit; 5. attach a mask on the faceofthe TV screen; if required for the game to be played; (1. begin thegame.

Referring now to FIG. 2, a television screen 18 is itlustrated havingthree spots 24 24 and 25 displayed thereon. Spots 24 are "hitting" spotsand spot 25 is a hit" spot. Spots 24, and 24 represent, for example.hockey players while spot 25 represents a hockey puck. An overlay mask3!) of some type of transparent matcrial such as plastic or the like.hmg some type of pattern. picture or other illustration pertaining tothe particular game to he played is shown in a lifted position. Prior toengaging in a game, the overlay mask is temporarily attached totelevision screen 18 and in such close proximity to it as not to createany distortion when viewed with reference to spots 24 and 25. One typeof overlay mask represents a hockey field to be used for playing amodified game of hockey. Still another pattern could represent aping-pong table. baseball diamond, etc. These are but a few of the manytype games that can be adapted for use with the present invcntion.

Alternatively. rather than employ overlay mask 30., the pattern to beprovided could be displayed directly on the screen 18. The pattern couldbe broadcast by TV stations or alternatively could be sent to a non-usedchannel over closcdcircu t or CATV lines. It could also be generatedelectronically in the video control system.

The basic theory of TV gaming devices as described herein is now setforth.

Referring to FIG. 3, at time zero the TV electron beam is at the upperleft of screen 18. It starts moving quickly to the right and slowlydownwards. Sixty-three and one-half (63.5) microseconds later a 5microsecond horizontal sync pulse is fed into the TV set, causing thebeam to fly back rapidly to the left of the screen. The beam then movesto the right for 63.5 microseconds until the next horizontal sync pulsecauses the next flyhack to the left. After about 250 such horizontalscans (lines) the beam has progressed to the bottom of the screen. Avertical sync pulse fed into the TV set causes rapid (l millisecond)vertical flyback to the top of the screen and another cycle begins.

Now. still referring to FIG. 3. assume that the major portion ofthescreen is dark (beam blanked) except for the areas shown as SPOT 1 andSPOT 2. The spots are made by passing a (positive) unblanking videosignal to the TV set when, and only when, the beam" is passing over theareas of the spots. [Quotes are used around beam because although thereis no real beam when blanking is in effect. the scanning signals OCCTSTand can he thought of as still moving the non-existent beam in thescanning pattern).

The video (unhlankingl signals required for spot generation as describedwith the aid of FIG. 3. To derive SPOT 1. assume that a pluse ofwidlh Wis generated Tm microseconds after the occurrence ofeach horizontal syncpulse. Define these new pulses as P hori zontal video pulse forSPOT l.lfthese P pulses were used as unblanking (video) in the TV set. the beamwould brighten whenever it had moved a distance equivalent to T from theleft side of the screen. If would stay bright for a length equivalent toW and then darken. This would happen all during the vertical scan andbright little line segments of width W would appear to the eye as avertical column l shown shaded in FIG. 3).

Now. SPOT 1 vertical video pulses P are made to be of width W, and tooccur T milliseconds after the start of the vertical sweep. W, is on theorder ololi microseconds. permitting some l0 horizontal scans to takeplace with P is on. If P were used alone as the unhlanking (video)signal to the TV set. ten lines the width ofthe set would be brightenedwhile P was on and a bright horizontal bar of width W (shown shaded inFEG. 3) would be viewed.

As the last step in spot generation, SPOT 1 horizontal video pulses Wand vertical video pulses (P are passed through a coincidence gate. Thegate has an output only when both P and P are on. The gate outputbecomes SPOT 1 video (unblank) signal. From FIG. 3 it is obvious thatthe beam is now unblanked only where the P vertical shaded column andthe P horizontal shaded bar overlap-Thus. a bright spot SPOT 1.comprised of about l0 small line segments. each W wide. is developed.SPOT 2 is developed in the like manner.

FIGS. 4 and 5 are block diagrams illustrating the manner in which thesignals discussed with respect to FIG. 3 are generated.

The timing for the television gaming system is establishcd by ahorizontal sync/sawtooth generator 31 and a vertical sync/sawtoothgenerator 32. The horizontal sync/sawtooth generator 31 generates aseries of negative l Jrizontal sync pulses 33 having a repetition rateequivalent to the standard horizontal scanning fre quency used in UnitedStates commercial television receivers and the vertical sync/sawtoothgenerator generates a series of negative vertical sync pulses 34.

The vertical snyc/sawtooth generator 31 also generates a 15.75 KHzsawtooth wave 35 (refer now to FIG. 5). Sawtooth wave 35 has end limitsof +E and 0. It is directly coupled to a SPOT 1 horizontal slicer 36. Aslicc of the sawtooth ramp of length W is passed through the slicer. Byvarying voltage e delay T can be varied for spot positioning from leftto right of the TV screen.

A 60Hz sawtooth 37 is generated by vertical synclsawtooth generator 32and is similarly sliced in a SPOT 1 vertical slicer 2). to give rampwidth W, and voltage controlled delay T The two sliced waves aredifferentiated by capacitors 38 and 39 which connect to the low inputimpedance of a SPOT 1 coincidence gate 40. Since the current through acapacitor is C de/dt. current pulses appear only during the rampportions of the sliced waveforms. Although the slope of the verticalramp is only about one two hundred and sixtieth times that of thehorizontal ramp (60 Hz/l5,750 HZ), by making capacitor 39 approximately260 times the value of capacitor 38. current plllsCS lll and i,, aremade equal in magnitude. Both in, and i must be present to exceed inmagnitude the (negative) thrcshold ofthe gate thus producing the SPOT]video signal.

1. In combination with a standard television receiver, apparatus forgenerating signals representing a symbol to be displayed on the screenof said television receiver, comprising: means for generating syncsignals; means for generating a first sawtooth wave; means forgenerating a second sawtooth wave; means coupled to said first sawtoothwave generating means for generating first current pulses proportionalto a predetermined slice of said first sawtooth wave; including a firstslicer having first and second diodes connected back-to-back with onejunction thereof coupled to said first sawtooth wave generating means, acapacitor coupled from the other junction to ground and means forreceiving a control signal at said other junction, and first means fordifferentiating the output from said first slicer; means coupled to saidsecond sawtooth wave generating means for generating second currentpulses proportional to a predetermined slice of said second sawtoothwave; including a second slicer having third and fourth diodes connectedback-toback with one junction thereof coupled to said second sawtoothwave generating means, a capacitor coupled from the other junction toground and means for receiving a control signal at said other junction,and second means for differentiating the output from said second slicer;a coincidence gate coupled to said first and second current pulsegenerating means; means for summing the output from said coincidencegate and said sync signals; an RF oscillator; means for modulating theoutput of said RF oscillator with said summed signal; and means forapplying said modulated signal to said receiver.
 2. Apparatus as definedin claim 1 wherein said first and second differentiating means includes:a first capacitor coupled from said first slicer to said coincidencegate; and a second capacitor coupled from said second slicer to saidcoincidence gate.
 3. Apparatus as defined in claim 1 wherein saidcoincidence gate includes: a transistor having first, second and thirdelectrodes, said third electrode being coupled to ground, with theoutput of said coincidence gate obtained at said third electrode; avoltage source; a first resistor coupled from said second electrode tosaid voltage source; a second resistor coupled from said secondelectrode to ground; and a third resistor coupled from said thirdelectrode to said voltage source.
 4. Apparatus as defined in claim 3wherein said second resistor is a variable resistor which adjusts thethreshold of said coincidence gate and thereby symbol size and shape. 5.Apparatus as defined in claim 4, further including means for generatingfirst and second control signals which determine said predeterminedslices, said control signals being coupled to said first and secondslicers.
 6. Apparatus as defined in claim 5 wherein said first andsecond control signal generating means includes: first and secondvoltage source; a first potentiometer coupled across said first voltagesource, the arm of said potentiometer being electrically coupled to saidfirst slicer; a second potentiometer coupled across said second voltagesource, the arm of said potentIometer being electrically coupled to saidsecond slicer; and means for adjusting the position of said arms tothereby vary said control signals.
 7. Apparatus as defined in claim 6wherein said adjusting means includes: a first knob coupled to said armof said first potentiometer; and a second knob coupled to said arm ofsaid second potentiometer.
 8. Apparatus as defined in claim 6 whereinsaid adjusting means includes a joystick coupled to both arms of saidpotentiometers.
 9. In combination with a standard television receiver,apparatus for generating signals representing a symbol to be displayedon the screen of said television receiver, comprising: a control unitincluding means for generating horizontal and vertical signalsrepresenting the symbol to be displayed, means for synchronizing atelevision raster scan, and means for manipulating the position of thesymbol on the screen, said manipulating means including means forgenerating first and second control signals coupled to said means forgenerating horizontal and vertical signals, said control signalgenerating means including means for automatically causing the displayedsymbol to travel back and forth between two predetermined positionsoff-screen; and means for electrically coupling said control unit tosaid television receiver.
 10. In combination with a standard televisionreceiver, apparatus for generating signals representing a symbol to bedisplayed on the screen of said television receiver comprising: acontrol unit including means for generating horizontal and verticalsignals representing the symbol to be displayed, means for synchronizinga television raster scan, and means for manipulating the position of thesymbol on the screen, said manipulating means including means forgenerating first and second control signals coupled to said means forgenerating horizontal and vertical signals, said control signalgenerating means including means for causing the displayed symbol totravel back and forth between two predetermined positions; and means forelectrically coupling said control unit to said television receiver;wherein said means for causing said displayed symbol to travel betweentwo predetermined positions includes: a bistable multivibrator having atleast a first input and first and second outputs; a first resistor; afirst diode, the anode thereof being coupled to one side of said firstresistor with the cathode thereof being coupled to the first output ofsaid bistable multivibrator; a second diode, the cathode thereof beingcoupled to the other side of said first resistor with the anode thereofbeing coupled to said second output of said bistable multivibrator; asecond resistor; a third diode, the cathode thereof being coupled to oneside of said second resistor with the anode thereof being coupled to thefirst output of said bistable multivibrator; a fourth diode, the anodethereof being coupled to the other side of said second resistor with thecathode thereof being coupled to said second output of said bistablemultivibrator; a third resistor; a fifth diode, the anode thereof beingcoupled to one side of said third resistor with the cathode thereofbeing coupled to the first output of said bistable multivibrator; asixth diode, the cathode thereof being coupled to the other side of saidthird resistor with the anode thereof being coupled to said secondoutput of said bistable multivibrator; a fourth resistor; a seventhdiode, the cathode thereof being coupled to one side of said fourthresistor with the anode thereof being coupled to the first output ofsaid bistable multivibrator; an eighth diode, the anode thereof beingcoupled to the other side of said fourth resistor with the cathodethereof being coupled to the second output of said bistablemultivibrator; means for applying triggering pulses to said first inputof said bistable multivibrator; means coupling said tHird and fourthresistors for providing a first control signal; and means coupling saidfirst and second resistors for providing a second control signal. 11.Apparatus as defined in claim 10 wherein said trigger applying meansincludes a slow free-running bistable multivibrator.
 12. Apparatus asdefined in claim 11 wherein the output from said slow free-runningbistable multivibrator is also applied to a second input of saidbistable multivibrator.
 13. Apparatus as defined in claim 10 whereinsaid resistors are variable.
 14. Apparatus as defined in claim 10,further including: a first RC network coupled to said means couplingsaid first and second resistors; and a second RC network coupled to saidmeans coupling said third and fourth resistors.
 15. Apparatus as definedin claim 10, further including: a first integrator coupled to said meanscoupling said first and second resistors; and a second integratorcoupled to said means coupling said third and fourth resistors. 16.Apparatus as defined in claim 5 wherein said first and second controlgenerating means includes means for generating a first sinusoid and asecond sinusoid phase displaced from said first sinusoid whereby thesymbol will traverse a path such as a circle, ellipse ''''figureeight'''' etc.
 17. Apparatus for generating signals representing a ''''hitting'''' symbol and a ''''hit'''' symbol to be displayed on thescreen of a television receiver, comprising: means for synchronizing atelevision raster scan; means for generating electrical signalsrepresenting a hitting symbol; means coupled to said means forgenerating signals representing a hitting symbol for generating firstand second control signals to vary the horizontal and vertical positionsof said hitting symbol; means for ascertaining coincidence between ahitting symbol and a hit symbol; first means for differentiating aportion of the signal output of said first control signal generatingmeans upon coincidence between said hitting symbol and said hit symbol;second means for differentiating a portion of the signal output of saidsecond control signal generating means upon coincidence between saidhitting symbol and said hit symbol; first means for integrating saidfirst differentiated signal for providing a first hit symbol controlvoltage; second means for integrating said second differentiated signaland for providing a second hit symbol control voltage; a hit symbolgenerator having as control inputs thereto said first and second hitsymbol control voltages whereby said hit symbol moves with a velocityproportional to the velocity of a hitting when coincident therewith. 18.Apparatus as defined in claim 17 further including first and second RCdelay circuits coupled to said first and second differentiating means,respectively.
 19. Apparatus as defined in claim 18, further includingmeans for reversing the polarity of said first and second hit symbolcontrol voltages when the outputs of said first and second integratorsreach at least a first predetermined voltage level.
 20. Apparatus asdefined in claim 19 wherein said polarity reversing means, includes: afirst and second comparators coupled to the outputs of said first andsecond integrators, respectively; means for applying reference signalsto said first and second comparators; and means for reversing thepolarity of the outputs of said differentiators responsive to outputs ofsaid comparators.
 21. Apparatus as defined in claim 20, furtherincluding first and second bistable multivibrators coupled to said firstand second comparators, respectively, the outputs of said bistablemultivibrators signifying the desired relative polarity of saidintegrator outputs.
 22. In combination with a standard televisionreceiver, apparatus for generating signals representing a first andsecond hitting symbol and a hit symbol to be displayed on the screen ofsaid television receiver, comprisinG: means for generating sync signals;means for generating a first sawtooth wave; means for generating asecond sawtooth wave; a first hitting symbol generator; a second hittingsymbol generator; a hit symbol generator; means for applying said firstand second sawtooth waves to said symbol generators; means forgenerating first and second control signals for said first hittingsymbol generator; means for coupling said first and second controlsignals to said first hitting symbol generator; means for generatingthird and fourth control signals for said second hitting symbolgenerator; means for coupling said third and fourth control signals tosaid second hitting symbol generator; means for generating fifth andsixth control signals for said hit symbol generator; means for couplingsaid fifth and sixth control signals to said hit symbol generator; meansfor coupling said first, second, third, and fourth control signals tosaid means for generating fifth and sixth control signals; and means forcoupling the outputs of said symbol generators and said sync signals tothe television receiver.
 23. Apparatus as defined in claim 22 whereinsaid means for generating fifth and sixth control signals includes:first means for detecting coincidence between said first hit symbol andsaid hitting symbol; second means for detecting coincidence between saidsecond hit symbol and said hitting symbol; a first monostablemultivibrator coupled to said first coincidence means; a secondmonostable multivibrator coupled to said second coincidence means;first, second, third, and fourth gates having as inputs thereto saidfirst, third, second, and fourth control signals, respectively; meansfor coupling the output of said first monostable multivibrator to saidfirst and third gates; means for coupling the output of said secondmultivibrator to said second and fourth gates; a first differentiatorcoupled to said first and second gates; a second differentiator coupledto said third and fourth gates; first sampling means coupled to saidfirst differentiator; second sampling means coupled to said seconddifferentiator; first and second OR gates, the outputs thereof beingcoupled to said first and second sampling means, respectively, theinputs thereof being coupled to both said monostable multivibrators;first and second peak detectors coupled to said first and secondsampling means, respectively; and first and second integrators coupledto said first and second peak detectors, respectively, said fifth andsixth control signals being derived at the outputs of said first andsecond integrators, respectively.
 24. Apparatus as defined in claim 23,further including: third and fourth OR gates, each coupled to both saidmonostable multivibrators; a first and second bistable multivibrator,each having first and second inputs, said first inputs taken at theoutputs of said third and fourth OR gates, respectively; a first andsecond comparator, the outputs thereof being coupled to second inputs ofsaid first and second bistable multivibrators, respectively; said firstand second comparators being coupled to said first and secondintegrators, respectively; means for generating reference voltages;means for applying said reference voltages to said comparators; andfirst and second means for reversing the polarity of the outputs of saidpeak detectors, said polarity reversing means coupled to the outputs ofsaid first and second bistable multivibrators, respectively.
 25. Incombination with a standard television receiver, apparatus forgenerating symbols upon the screen of the receiver to be manipulated byat least one participant, comprising: means for generating a hittingsymbol, and means for generating a hit symbol including means forascertaining coincidence between said hitting symbol and said hit symboland means for imParting a distinct motion to said hit symbol uponcoincidence.
 26. The combination of claim 25 wherein said means forgenerating a hitting symbol includes means for providing horizontal andvertical control signals for varying the horizontal and verticalpositions of said hitting symbol.
 27. The combination of claim 26wherein said means for providing horizontal control signals includes avoltage source, a potentiometer coupled across said voltage source andan integrator coupled to the arm of said potentiometer, said controlsignal being derived at the output of said integrator.
 28. Thecombination of claim 25 wherein said means for generating a hit symbolincludes means for providing horizontal and vertical control signals forvarying the horizontal and vertical positions of said hit symbol. 29.The combination of claim 28 wherein said means for providing horizontalcontrol signals for said hit symbol includes means for causing said hitsymbol to move back and forth across the screen when triggered.
 30. Thecombination of claim 29 wherein said triggering means includes a slowfree-running multivibrator.
 31. The combination of claim 29 furtherincluding means for detecting coincidence between a hit symbol and ahitting symbol and means for causing said hit symbol to change directionupon coincidence.
 32. The combination of claim 25 wherein said means forgenerating a hit symbol further includes means for causing said hitsymbol to move away from a predetermined position of the screen with areflection angle equal to the incident angle at which said hit symbolapproached said predetermined position.
 33. In combination with astandard television receiver, apparatus for generating signalsrepresenting a symbol to be displayed on the screen of said televisionreceiver, comprising: means for generating sync signals; means forgenerating a first sawtooth wave; means for generating a second sawtoothwave; means coupled to said first sawtooth wave generating means forgenerating first current pulses proportional to a predetermined slice ofsaid first sawtooth wave; including a first slicer having first andsecond diodes connected back-to-back with one junction thereof coupledto said first sawtooth wave generating means, a capacitor coupled fromthe other junction to ground and means for receiving a control signal atsaid other junction, and first means for differentiating the output fromsaid first slicer; means coupled to said second sawtooth wave generatingmeans for generating second current pulses proportional to apredetermined slice of said second sawtooth wave; including a secondslicer having third and fourth diodes connected back-to-back with onejunction thereof coupled to said second sawtooth wave generating means,a capacitor coupled from the other junction to ground and means forreceiving a control signal at said other junction and second means fordifferentiating the output from said second slicer; a coincidence gatecoupled to said first and second current pulse generating means; meansfor summing the output from said coincidence gate and sync signals;means for applying the output of said summing means to the video andsync circuits of said television receiver.
 34. Apparatus as defined inclaim 33, further including means for disconnecting the video detectorof said television receiver from said video amplifier.
 35. Incombination with a standard television receiver, apparatus forgenerating signals representing a first and second hitting symbol and ahit symbol to be displayed on the screen of said television receiver,comprising: means for generating a first sawtooth wave; means forgenerating a second sawtooth wave; a first hitting symbol generator; asecond hitting symbol generator; a hit symbol generator; means forapplying said first and second sawtooth waves to said symbol generators;means for generating first and second control signals for said firsthitting generatOr; means for coupling said first and second controlsignals to said first hitting symbol generator for changing the positionthereof; means for generating third and fourth control signals for saidsecond hitting symbol generator; means for coupling said third andfourth control signals to said second hitting symbol generator forchanging the position thereof; (means for applying the output of saidspot generator to the video amplifier of said television receiver.)means for generating fifth and sixth control signals for said''''hit'''' symbol generator; means for coupling said fifth and sixthcontrol signals to said ''''hit'''' symbol generator for changing theposition thereof; means for coupling said first, second, third andfourth control signals to said means for generating fifth and sixthcontrol signals such that the motion of said ''''hit'''' symbol isdependent on the position of a ''''hitting'''' symbol; and means forcoupling the outputs of said symbol generators to the video amplifier ofsaid television receiver.
 36. In combination with a conventionaltelevision receiver, apparatus for generating signals representing asymbol to be displayed on the screen of said television receiver,comprising: means for generating vertical and horizontal sawtoothwaveforms; means for synchronizing said vertical and horizontal sawtoothwaveforms to the sync signals received in said television receiver froma broadcast signal; a spot generator including a first slicer havingfirst and second diodes connected back-to-back with one junction thereofcoupled to said vertical sawtooth generating means, a capacitor coupledfrom the other junction to ground and means for receiving a firstcontrol signal at said other junction, and first means fordifferentiating the output from said first slicer, and a second slicerhaving third and fourth diodes connected back-to-back with one junctionthereof coupled to said horizontal sawtooth generating means, acapacitor coupled (form) from the other junction to ground and means forreceiving a second control signal at said other junction, and secondmeans for differentiating the output from said second slicer, and acoincidence gate coupled to said first and second differentials; andmeans for applying the output of said spot generator to the videoamplifier of said television receiver.
 37. The combination of claim 36,wherein said means for generating vertical and horizontal sawtoothwaveforms includes means coupled to the horizontal and verticaldeflection circuits of said television receiver.
 38. Apparatus forgenerating symbols upon the screen of a cathode ray tube, comprising: acathode ray tube; means for generating horizontal and vertical syncsignals; means for generating first and second sawtooth waves; means forgenerating a video signal proportional to predetermined slices of saidsawtooth waves including a first slicer having first and second diodesconnected back-to-back with one junction thereof coupled to saidvertical sawtooth generating means, a capacitor coupled from the otherjunction to ground and means for receiving a first control signal atsaid other junction, and first means for differentiating the output fromsaid first slicer, and a second slicer having third and fourth diodesconnected back-to-back with one junction thereof coupled to saidhorizontal sawtooth generating means, a capacitor coupled from the otherjunction to ground and means for receiving a second control signal atsaid other junction, and second means for differentiating the outputfrom said second slicer, and a coincidence gate coupled to said firstand second differentials; a horizontal deflection circuit coupled tosaid cathode ray tube; a vertical deflection coupled to said cathode raytube circuit; means for coupling said video signal to the intensityinput of said cathode ray tube; means for coupling said horizontal syncsignals to said horizontal deflection circuits; and means for couplingsaid vertical sync signals to said vertical deflection circuit. 39.Apparatus as defined in claim 38, further including means for supplyinghigh voltage to said cathode ray tube.
 40. Apparatus as defined in claim39 wherein said video signal coupling means includes a video amplifier.(44.)
 41. Apparatus for playing ping-pong type games by displaying andmanipulating symbols on the screen of a cathode ray tube, comprising:means for generating a first hitting spot; means for generating a secondhitting spot; means for generating a hit spot; means for changing thevertical position of said first hitting spot; means for changing thevertical position of said second hitting spot; means for causing saidhit spot to move from an off-screen left position to an off-screen rightposition and vice versa; means for changing said off-screen right andoff-screen left positions; means for denoting coincidence between saidfirst hitting spot and said hit spot; means for denoting coincidencebetween said second hitting spot and said hit spot; means for causingsaid hit spot to change horizontal direction upon coincidence betweensaid hit spot and either of said hitting spots; and means for displayingsaid spots upon the screen of said cathode ray tube.
 42. The apparatusof claim 41 further including means for causing said hit spot to moveon-screen subsequent to said hit spot moving off-screen occurring whensaid hit spot does not make coincidence with one of said hitting spotswhen in vertical alignment therewith.
 43. Apparatus for playing a gunping-pong type game on the screen of a cathode ray tube, comprising:means for generating a hit spot; a first light sensitive gun; a secondlight sensitive gun; means for causing said hit spot to move from anoff-screen right to an off-screen left position and vice versa; meansfor causing said hit spot to change direction when one of said lightguns receives a pulse of light energy from said hit spot; and means forserving said hit spot when said hit spot goes off-screen.
 44. Apparatusfor playing a baseball type game on the screen of a cathode ray tube,comprising: means for displaying a hit spot; means for displaying ahitting spot; means for adjusting the vertical position of said hittingspot; means for serving said hit spot; and means for varying thevertical position of said hit spot; and means for denoting coincidencebetween said hit and said hitting spot whereby said hit spot willreverse directions.
 45. Apparatus for playing a hockey type game uponthe screen of a cathode ray tube, comprising: means for displaying afirst hitting spot; means for displaying a second hitting spot; meansfor displaying a hit spot; means for controlling the position of saidfirst and second hitting spots; means for controlling the position ofsaid hit spot including means for ascertaining coincidence betweeneither of said hitting spots and said hit spot and means for imparting adistinct motion to said hit spot upon coincidence.
 46. Apparatus asdefined in claim 45 wherein said means for controlling said hit spotincludes means for causing said hit spot to move in the direction hit bya hitting spot and means for causing said hit spot to bounce away fromthe sides of said cathode ray tube when coincidence therewith. 47.Apparatus for playing a simulated handball game upon the screen of acathode ray tube, comprising: means for displaying a first symbolrepresenting a first player; means for displaying a second symbolrepresenting a second player; and means for displaying a third symbolrepresenting a ball; means for controlling the position of said firstsymbol on said cathode ray tube; means for controlling the position ofsaid seCond symbol on said cathode ray tube; means for controlling theposition of said third symbol on said cathode ray tube; said means forcontrolling the position of said third symbol on said cathode ray tubeincluding means for causing said third symbol to change direction uponcoincidence between either of said first or second symbols and means forcausing said third symbol to bounce off three of said four sides of saidcathode ray tube upon coincidence therewith and to go off-screen whencoincident with said fourth side of said cathode ray tube; and means forserving said third symbol when it goes off-screen at said fourth side ofsaid cathode ray tube.
 48. Apparatus for generating signals representinga symbol to be displayed on the screen of a television receiver,comprising: means for generating sync signals; means for generating afirst sawtooth wave; means for generating a second sawtooth wave; meanscoupled to said first sawtooth wave generating means for generatingfirst current pulses proportional to a predetermined slice of said firstsawtooth wave including a first slicer having first and second diodesconnected back-to-back with one junction thereof coupled to said firstsawtooth wave generating means, a capacitor coupled from the otherjunction to ground and means for receiving a control signal to saidother junction, and first means for differentiating the output from saidfirst slicer; means coupled to said second sawtooth wave generatingmeans for generating second current pulses proportional to apredetermined slice of said second sawtooth wave including a secondslicer having third and fourth diodes connected back-to-back with onejunction thereof coupled to said second sawtooth wave generating means,a capacitor coupled from the other junction to ground and means forreceiving a control signal at said other junction, and second means fordifferentiating the output from said second slicer; a coincidence gatecoupled to said first and second current pulse generating means; meansfor coupling the output from said coincidence gate and said sync signalsto a television receiver.
 49. Apparatus for generating signalsrepresenting a hitting symbol and a hit symbol to be displayed on thescreen of a television receiver, comprising: means for generatingsynchronizing signals; means for generating electrical signalsrepresenting a hitting symbol; means coupled to said means forgenerating electrical signals representing a hitting symbol forgenerating first and second control signals to vary the horizontal andvertical positions of said hitting symbol; first means fordifferentiating a portion of the signal output of said first controlsignal generating means; second means for differentiating a portion ofthe signal output of said second control signal generating means; firstmeans for integrating said first differentiated signal for providing afirst hit symbol control voltage; second means for integrating saidsecond differentiated signal and for providing a second hit symbolcontrol voltage; and a symbol generator having as control inputs theretosaid first and second hit symbol control voltages whereby said hitsymbol moves with a velocity proportional to the velocity of saidhitting symbol when coincident therewith.
 50. Apparatus for generatingsignals representing a first and second hitting symbol and a hit symbolto be displayed on the screen of a television receiver, comprising:means for generating sync signals; means for generating a first sawtoothwave; means for generating a second sawtooth wave; a first hittingsymbol generator; a second hitting symbol generator; a hit symbolgenerator; means for applying said first and second sawtooth waves tosaid symbol generators; means for generating first and second controlsignals for said first hitting symbol generator; means for coupling saidfirst and second control signals to saId first hitting symbol generator;means for generating third and fourth control signals for said secondhitting symbol generator; means for coupling said third and fourthcontrol signals to said second hitting symbol generator; means forgenerating fifth an sixth controls signals for said hit symbolgenerator; means for coupling said fifth and sixth control signals tosaid hit symbol generator; means for coupling said first, second, third,and fourth control signals to said means for generating fifth and sixthcontrol signals; and means for coupling the outputs of said symbolgenerators and said sync signals to a television receiver.
 51. Apparatusfor generating symbols upon the screen of a television receiver to bemanipulated by at least one participant, comprising: means forgenerating a hitting symbol; and means for generating a hit symbolincluding means for ascertaining coincidence between said hitting symboland said hit symbol and means for imparting a distinct motion to saidhit symbol upon coincidence.
 52. The combination of claim 51 whereinsaid means for generating a hitting symbol includes means for providinghorizontal and vertical control signals for varying the horizontal andvertical positions of said hitting symbol.
 53. The combination of claim52 wherein said means for providing horizontal control signals includesa voltage source, a potentiometer coupled across said voltage source andan integrator coupled to the arm of said integrator, said control beingderived at the output of said integrator.
 54. The combination of claim51 wherein said means for generating a hit symbol includes means forproviding horizontal and vertical control signals for varying thehorizontal and vertical positions of said hit symbol.
 55. Thecombination of claim 54 wherein said means for providing horizontalcontrol signals for said hit symbol includes means for causing said hitsymbol to move back and forth across the screen.
 56. The combination ofclaim 55 wherein said means for causing said hit symbol to move back andforth across the screen includes a slow free-running multivibrator. 57.The combination of claim 55 further including means for detectingcoincidence between a hit symbol and a hitting symbol and means forcausing said hit symbol to change direction upon coincidence. 58.Apparatus for generating signals representing a symbol to be displayedon the screen of a television receiver, comprising: means for generatingsync signals; means for generating a horizontal sawtooth wave; means forgenerating a vertical sawtooth wave; means coupled to said horizontalsawtooth wave generating means for generating first current pulsesproportional to a predetermined slice of said horizontal sawtooth waveincluding a first slicer having first and second diodes connectedback-to-back with one junction thereof coupled to said horizontalsawtooth wave generating means, a capacitor coupled from the otherjunction to ground and means for receiving a control signal at saidother junction, and first means for differentiating the output from saidfirst slicer; means coupled to said vertical sawtooth wave generatingmeans for generating second current pulses proportional to apredetermined slice of said vertical sawtooth wave including a secondslicer having third and fourth diodes connected back-to-back with onejunction thereof coupled to said vertical sawtooth wave generatingmeans, a capacitor coupled from the other junction to ground and meansfor receiving a control signal at said other junction and second meansfor differentiating the output from said second slicer; a coincidencegate coupled to said first and second current pulse generating means;means for summing the output from said coincidence gate and syncsignals; means for applying the output of said summing means to thevideo amplifier of a television receiver.
 59. Apparatus for generatingsignals representing a first and second hItting symbol and a hit symbolto be displayed on the screen of a television receiver, comprising;means for generating a first sawtooth wave; means for generating asecond sawtooth wave; a first hitting symbol generator; a second hittingsymbol generator; a hit symbol generator; means for applying said firstand second sawtooth waves to said symbol generators; means forgenerating first and second control signals for said first hittingsymbol generator; means for coupling said first and second controlsignals to said first hitting symbol generator; means for generatingthird and fourth control signals for said second hitting symbolgenerator; means for coupling said third and fourth control signals tosaid second hitting symbol generator; means for generating fifth andsixth control signals for said hit symbol generator; means for couplingsaid fifth and sixth control signals to said hit symbol generator; meansfor coupling said first, second, third, and fourth control signals tosaid means for generating fifth and sixth control signals; and means forcoupling the outputs of said symbol generators to the video amplifier ofa television receiver.
 60. Apparatus for playing games by displaying andmanipulating symbols on the screen of a cathode ray tube comprising:means for generating vertical and horizontal synchronization signals;means responsive to said synchronization signals for deflecting the beamof said cathode ray tube to generate a raster on said screen; meanscoupled to said synchronization signal generating means and said cathoderay tube for generating a first symbol on said screen at a positionwhich is directly controlled by a player; means coupled to saidsynchronization signal generating means and said cathode ray tube forgenerating a second symbol on said screen which is movable; meanscoupled to said first symbol generating means and said second symbolgenerating means for determining a first coincidence between said firstsymbol and said second symbol; and means coupled to said coincidencedetermining means and said second symbol generating means for impartinga distinct motion to said second symbol in response to said coincidence.61. The apparatus of claim 60, further including: means coupled to saidsynchronization signal generating means and said cathode ray tube forgenerating a third symbol on said screen at a position which iscontrolled by a player; means coupled to said third symbol generatingmeans and said second symbol generating means for determining a secondcoincidence between said third symbol and said second symbol; and meanscoupled to said second and third symbol coincidence determining meansand said second symbol generating means for imparting a distinct motionto said second symbol in response to said second coincidence.
 62. Theapparatus of claim 61 further including means for causing said secondsymbol to travel across said screen from one side of said raster toanother side of said raster in the absence of an occurrence ofcoincidence between said second symbol and said first or third symbolafter coincidence of said second symbol with said third or first symbol.63. The apparatus of claim 61, further including: means for determininga third coincidence of a signal representing said second symbol and asignal bearing a specific time relationship with an edge of said raster;and means coupled to said third coincidence determining means and saidsecond symbol generating means for altering the motion of said secondsymbol in response to said third coincidence.
 64. The apparatus of claim63 wherein said motion altering means imparts to said second symbol amotion which is a reflection of its motion immediately prior to itsmotion at said third coincidence.